New measurement of the 3He(α,γ)7Be cross section at medium energies

We report on a new cross-section measurement for the He-3(alpha, gamma)(7) Be reaction at three medium energies of E-c.m. between 1 and 3 MeV. The interest stems from the significant role played by the reaction in calculating an accurate solar neutrino flux and the primordial Li-7 abundance. The energy dependence of the astrophysical S-34 factor observed in the present work, especially above 1 MeV, highlights the need to constrain theories in order to obtain a precise extrapolated value for S-34(0). In this context, a comparison with the recent theoretical work in a fully microscopic fermionic molecular dynamics approach and a few other representative calculations emphasize the need for further experimental as well as theoretical work to resolve the existing conflicts.